Former Cuban president Fidel Castro has said that climate change is more serious than the international economic crisis which was the main subject of G20 summit in London.

Former Cuban president Fidel Castro has said that climate change is more serious than the international economic crisis which was the main subject of on Thursday's G20 summit in London.

"The financial crisis is not the only problem. There's another worse one, because it has to do not with the means of production and distribution but with our very existence. I'm referring to climate change," Castro said in the latest of his commentaries on current events.

"Both are in Havana and will be discussed simultaneously," he stressed.

In his column, he analysed the prospects for the G20 summit and the imminent negotiations about climate change in Bonn.

Regarding the G20, the leftist leader said earlier that the conclave in London is "the classic among the biggest economies in the world, the most developed and those that are developing", and that "the rules of the game are not very clear".

The 82-year-old leader, who formally stepped down last year in favour of younger brother Raul Castro, also pointed out the friction between G20 leaders over the regulation of the international system.

Citing a report by the Britain based charity Oxfam, Castro said the $8.42 trillion public money committed by the governments of the rich world to rescue the banking sector could have been used to eliminate world poverty in the next 50 years.

Regarding the ongoing climate change meeting in Bonn, Castro said he was not quite hopeful of its success.

"Strong contradictions exist regarding the contribution that the economies should make," Castro said, referring to arguments between the rich world and emerging powers such as China and India, whose leaders say the brunt of the cost of reducing greenhouse emissions should be borne by Europe and the US.

He added that while the Antarctic ice cap is melting at a faster rate, the "sceptics are crying that the scientists are exaggerating" and continue to dream "such feeble hopes".

Fidel Castro was sidelined in July 2006 by a near fatal intestinal illness. During his convalescence, he began writing "Reflections" on a wide range of matters.